An annual battle with the prolific pink pest

David Overend

They’re out in force, bashing, cutting, hacking, uprooting and generally knocking eight bells out of an attractive but unpopular plant.

We all make mistakes. Thankfully, we tend learn from them and get on with our lives – and try to forget. But sometimes, the consequences never go away – and that’s why volunteers throughout Yorkshire (and other parts of the country) are working to rid the land of Impatiens glandulifera, Himalayan balsam.

Back in 1839, some bright spark thought it would be a great idea it to UK gardens. It proved very popular – until it escaped to find new homes in the countryside.

Now Himalayan balsam is a naturalised plant, found especially on riverbanks and streamsides where it has become a massive problem because it tolerates low light levels and also grows tall enough to shade out most other vegetation, so native plants stand little chance of competing with it for space and they quickly fade away.

In late summer, Himalayan balsam stems (anything up to 10 feet in height) are topped with delicate pink flowers. Unfortunately, these produce thousands of seeds which are scattered far and wide to produce even more invasive plants.

That’s why stream and river banks and wild areas where the soil is damp enough to suit its needs, are clothed in this pernicious annual – and it’s a never-ending battle to control its spread.

Pulling or cutting the plants before they flower and set seed is hard work, and the only other way is to use chemicals before the flowers set seed. Probably the best is one containing glyphosate, which works its way through the foliage to kill the roots.